JPH06200563A - Construction method for trussed structure - Google Patents

Abstract

PURPOSE:To simplify a construction work for a trussed structure, and substantially reduce construction cost by allowing the axial center of a shaft member to deviate from a joint, and connecting the joint members of adjacent units to each other. CONSTITUTION:An approximately triangular grid is constituted of three shaft members 1 and three joint members 2, and used as one truss unit A. The units A so constituted are arranged on the prescribed curved surface at every other positions, and the joint members 2 are connected to each other, thereby forming a monolayer lattice shell as a trussed structure. As a result, three joint members 2 gather at each joint (a), and the axial center of each shaft member 1 comes to deviate from the center of the joint (a).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a truss structure such as a single-layer lattice shell structure or a multi-layer space truss structure.

[0002]

2. Description of the Related Art In a truss structure, when assembling a shaft member such as a steel pipe, a ball joint of a type in which multidirectional shaft members are gathered at one point is often used as a joint member at a node. FIG. 14 schematically shows a part of a single-layer lattice shell as such a truss structure, in which 1 is a shaft member as a truss member and 2 is a joint member composed of a ball joint. Regarding the ball joint, various structures have been developed, but it is common to provide a connection hole for inserting the end of the shaft member in the connecting direction of the shaft member and connect using a bolt or the like. Is.

Also, when a shaped steel or the like other than the steel pipe is used as the shaft member, the axis centers of the multidirectional shaft members are usually concentrated at the nodes.

As a method of constructing such a truss structure, a method is generally used in which support members and scaffolds are assembled and the shaft members are sequentially connected by joint members such as ball joints.
To minimize work in the air, assemble a unit consisting of multiple shaft members and joint members of a certain size on the ground, lift this unit with a crane, etc., and connect the units with joint members. There are also ways to go. In addition, some of these units incorporate scaffolding and safety nets.

[0005]

When a joint member such as a ball joint is used, conventionally, the shaft centers of the shaft members are gathered at the centers of the nodes, and eccentricity is avoided as much as possible.
It is designed to prevent the rigidity and strength of the entire truss structure from decreasing.

However, at a node where a large number of shaft members are concentrated, a joint member such as a ball joint becomes large, while connection is possible by reducing the diameter of the end portion of each shaft member. This leads to a decrease in the strength of the connecting portion, and there is a problem in that it costs too much to process the joint member and each shaft member.

Further, a large-scale scaffold is required to assemble the truss structure from each member and joint level, and at present, the occupancy cost is extremely high.
Therefore, if the work is divided into assembling the basic unit on the ground and joining them in space, it is considered that the construction cost will be significantly reduced. However, even when the units are united, it is difficult to connect the shaft members that gather at the nodes with one joint member, regarding the nodes between the units. In particular, when connecting large units, it is more difficult to connect structurally unstable units than connecting shaft members one by one, and the advantages of unitization can be fully utilized. There is a problem that there is no.

The present invention permits the construction of a truss structure by allowing the truss units having a stable shape to be eccentric at the nodal points of the shaft members and connecting the joint members of the adjacent units. The construction cost is simplified and the construction cost is greatly reduced.

[0009]

A method of constructing a truss structure according to the present invention provides a truss unit having a structurally stable shape by connecting a plurality of shaft members constituting the truss structure with a plurality of joint members. Assembling, the truss units are connected to each other in a state where the joint members constituting the truss unit are in close contact with or close to each other, and are sequentially connected.

That is, the structure is constructed by connecting and constructing a part of frames constituting the structure of the truss structure as a basic unit, and at the nodes connecting the truss units, the axes of the assembled shaft members are all 1 Rather than concentrating on points, the joint members of each truss unit are gathered, so some eccentricity is allowed. Therefore, the nodes for joining the units are usually composed of two or more joint members such as 2, 3, 4, etc. However, not all of the joints connecting the truss units have to be composed of two or more joint members, and in combination with the joints composed of two or more joint members, a single joint connected by a shaft member is used. In some cases, a node composed of a joint member may occur.

When the joint points are composed of two or more joint members, eccentricity occurs at the joint points, but the influence of the eccentricity such as passing the shaft center of the shaft member as the truss member on the same line depending on the configuration and arrangement of the unit is affected. It is possible to reduce it as much as possible. In addition, eccentricity at the node of the truss unit joint is expected to weaken the rigidity of the truss structure and reduce its strength, but stress concentration between the shaft members that make up the truss is reduced, and so on. There is also an element of, so it does not become so negative. In particular, when not only the initial rigidity and strength of the truss structure but also the flexibility of the entire frame is required from the viewpoint of seismic performance, it is conceivable to use this kind of eccentricity in reverse.

By connecting the joint members at the unit joints and allowing eccentricity at the nodes, structurally stable units can be manufactured before erection, and each unit maintains its shape and rigidity. Since it is erected in a closed state, it is easy to construct. Therefore, it is possible to fully utilize the advantages of unitizing the basic unit on the ground and joining them in space, which leads to a significant reduction in erection cost.

The truss unit constituting the basic unit is 1
Not only the grid but a few grids or more may be used. As the simplest one, for example, a polygonal shape such as a triangle, a quadrangle, or a hexagon, or a pyramid such as a triangular pyramid or a quadrangular pyramid can be considered. It is also possible to join truss units having different shapes or different shapes, and the truss units may be designed according to the shape and scale of the truss structure to be constructed.

In the multi-layer truss structure, a method of separately assembling and joining the upper and lower layers and the intermediate layer may be considered. For example, an upper chord member truss unit formed by connecting a plurality of upper chord members with a joint member, a lower chord member truss unit formed by connecting a plurality of lower chord members with a joint member, and a plurality of belly members connected with a joint member The multi-layer truss structure can be constructed with good workability by assembling the abdomen truss units separately with a certain size and connecting these by connecting the joint members.
In addition to this, for example, a two-stage type in which a truss unit is composed of a plurality of lower chord members and a plurality of belly members, and an upper chord member truss unit is connected thereto is also possible.

The joint members gathering at one node may be joined in close contact with each other so as to minimize the eccentricity, or may be joined to each other via joint fittings to keep a certain distance. In the latter case, by adjusting the length of the joint fitting, each truss unit can be adapted to various curved surfaces, provided with a peeling, and variously used.

[0016]

EXAMPLES Next, the illustrated examples will be described.

FIG. 1 shows a part of a truss structure having a single-layer lattice shell structure constructed by the construction method of the present invention.

In this embodiment, the three shaft members 1 and the three joint members 2 that join them together form a grid of substantially equilateral triangles, which is regarded as one truss unit A.

Units A, which form a substantially equilateral triangle, are arranged alternately on a predetermined curved surface to form a single-layer lattice shell, and three joint members 2 gather at each node a,
It is joined.

FIG. 2 shows the relationship between the node a and the joint member 2. (a) corresponds to FIG. 1, and the shaft members 1 of the truss unit A having a substantially equilateral triangle are the same for the adjacent units A. An example in which they are arranged on a straight line, (b) is an example in which each shaft member 1 is arranged at a node a where three joint members 2 gather, and the axes are slightly displaced.

FIG. 3 shows a truss unit A, which is a basic structure in the case of constructing a truss structure having a single-layer lattice shell structure according to the present invention, into a substantially regular hexagon. Each truss unit A is composed of twelve shaft members 1 and seven joint members 2 for joining them, and is composed of six triangular grids. The joint between truss units A is two joint members 1. Do in between.

FIG. 4 shows a single-layer lattice shell in which substantially square truss units A each consisting of five shaft members 1 including a diagonal member 1'and four joint members 2 are closely arranged to form a single-layer lattice shell. By the construction method of, it is possible to make a curved surface having arbitrary irregularities. In this case, the two shaft members 1 are parallel to each other in the adjacent truss units A, and the four joint members 2 formed of ball joints gather at the node a.

FIGS. 5 and 6 show a part of a truss structure having a two-layer space truss structure constructed by the construction method of the present invention.

In the present embodiment, a regular quadrangular pyramid is manufactured as one truss unit A, and the truss units are assembled to form a truss structure. The truss units A are joined to each other by joining the four joint members 2 in the upper layer,
In the lower layer, the joint members 2 at the apexes of the cones are connected by one shaft member 3.

7 and 8 show another method for forming a truss structure having a two-layer space truss structure. One truss unit A is composed of an X-shaped unit including upper and lower chord members, and unit A They are assembled by joining the four joint members 2 and the diagonal member 4 arranged between the central nodes 2 of the X-shaped units A.

FIGS. 9 and 10 show another method of forming a truss structure having a multi-layer space truss structure. The truss structure is composed of upper and lower chord members and an intermediate belly member. The three-layer truss is constructed by separating three parts from each other and assembling them in a certain unit.

That is, an upper chord member truss unit U formed by connecting a plurality of upper chord members 1 _u by a joint member 2 _u and a lower chord member truss unit L formed by connecting a plurality of lower chord members 1 _l by a joint member 2 _l. , The abdominal material truss unit M in which a plurality of abdominal materials 1 _m are connected by the joint member 2 _m is connected by connecting the joint members 2 _u , 2 _l , 2 _m . In this case, the axis of the upper and lower chord 1 _u, 1 _l, and the joint member 2 _m connecting was what web members 1 _m are bonded in a state of being eccentric.

FIG. 11 exemplifies a case where four joint members 2 made of ball joints are gathered as a node a where each truss unit A is gathered, which is common to the single-layer lattice shell structure and the multi-layer space truss structure. (a) is an example in which four joint members 2 are adhered to each other so as to minimize the eccentricity at the node a, and are fastened inside the sphere of the member with bolts 5, (b) shows the four joint members 2 from the outside. In this example, the screw member 6 that can be operated is used for joining.

FIG. 12 schematically shows a case where a plate-shaped block forming a space truss is considered as the truss unit A, and these blocks are assembled and assembled. At the joint portion of adjacent plate-shaped truss units A, the length can be adjusted, for example, by adjusting the length of the joint fitting for joining the joint members. FIG. 13 (a) shows an example of such a joint fitting 7. Further, in order to suppress the decrease in rigidity caused by the clearance between the plate-shaped truss units A, as shown in FIG. 13 (b), a vertical member 8 shared by both truss units A is provided between the upper and lower nodes a. It is also possible.

[0030]

[Effects of the Invention] By allowing eccentricity at the nodes, structurally stable truss units can be connected to each other, and since they can be joined while maintaining their shape and rigidity, the workability is greatly improved and construction work can be performed. It is possible to maximize the advantages of unitization such as simplification and reduction of construction cost.

Since the joint point between the truss units has a plurality of joint members, the concentration of the shaft member as the truss member on the joint member is relieved, which is advantageous in terms of structure and workability. The joint member and each shaft member can be easily processed and can be manufactured at low cost.

By improving the workability and greatly reducing the work cost, it is possible to compensate the disadvantage in the structure due to the eccentricity in terms of design.

[Brief description of drawings]

FIG. 1 is a perspective view showing a part of a truss structure constructed by a construction method of the present invention.

2 (a) and 2 (b) are plan views showing the relationship between nodes and truss members, respectively.

FIG. 3 is a perspective view showing another example of a truss structure constructed by the construction method of the present invention.

FIG. 4 is a perspective view showing still another example of a truss structure constructed by the construction method of the present invention.

FIG. 5 is a plan view showing still another example of a truss structure constructed by the construction method of the present invention.

FIG. 6 is a perspective view corresponding to FIG.

FIG. 7 is a plan view showing still another example of a truss structure constructed by the construction method of the present invention.

8 is a perspective view corresponding to FIG. 7. FIG.

FIG. 9 is a front view showing still another example of the truss structure constructed by the construction method of the present invention.

FIG. 10 is a plan view of each of upper, lower, and middle layers corresponding to FIG.

11 (a) and 11 (b) are cross-sectional views showing an example of a node composed of four ball joints.

FIG. 12 is a schematic view of a case where plate-shaped truss units are assembled and assembled.

13 (a) and 13 (b) are cross-sectional views of a truss unit joint portion corresponding to FIG. 12, respectively.

FIG. 14 is a perspective view schematically showing a part of a conventional single-layer lattice shell.

[Explanation of symbols]

A ... Truss unit, a ... Node, U ... Upper chord truss unit, L ... Lower chord truss unit, M ... Abdominal truss unit, 1 ... Shaft member, 2 ... Joint member, 3 ... Shaft member,
4 ... diagonal members, 5 ... bolt, 6 ... screw member, 7 ... metal joint, 8 ... vertical members, 1 _u ... upper chord member, 1 _l ... lower chord member, 1
_m … Belly material, 2 _u , 2 _l , 2 _m … Joint member,

Claims (4)

[Claims] 1. A truss unit having a structurally stable shape is assembled by connecting a plurality of shaft members with a plurality of joint members, and the truss units are brought into close contact with or close to each other of the joint members constituting the truss unit. A method for constructing a truss structure, which is characterized in that the truss structures are connected in a state of being connected and are sequentially connected. 2. The method for constructing a truss structure according to claim 1, wherein each truss unit is assembled in a polygonal shape. 3. The method for constructing a truss structure according to claim 1, wherein each truss unit is assembled into a polygonal pyramid. 4. An upper chord member truss unit formed by connecting a plurality of upper chord members with a joint member, a lower chord member truss unit formed by connecting a plurality of lower chord members with a joint member, and a plurality of belly members connected with a joint member. A method of constructing a truss structure, characterized in that the abdominal truss units formed by the above are connected by connecting the joint members.